In dentistry, various capsules are known for the preparation and/or delivery of dental materials consisting of one component or of two or more components which are to be mixed together. There are single-component capsules, powder/liquid capsules, and paste/paste capsules.
A compule is a capsule having a cannula, a single chamber containing a one-component material with an opening at the front into the cannula, and a piston which sits in the rear of the chamber. Such compules can contain, for example, the universal filler material Filtek™ Supreme and the universal composite Filtek™ Z250 available from 3M ESPE. For use, the capsule has to be inserted into an applicator which, for example, is available from 3M ESPE as Capsule dispenser under article number 5706 SD, or from Centrix under the designation Mark IIIp™. These known applicators each have a body with a handgrip, a holder for receiving the compule in a removable manner, a plunger, and a drive mechanism for the plunger. When the capsule sits in the holder and the drive mechanism is actuated by hand, the drive mechanism pushes the plunger into the chamber from the rear, so that the plunger initially bears on the piston and pushes it forwards. The material is dispensed from the chamber through the cannula due to the advancement of the piston.
The liquid/powder capsules contain a liquid component and a powder component which have to be kept separate from one another until the time of use. Such liquid/powder capsules are, for example, available under the names Aplicap™ and Maxicap™ from 3M ESPE. These capsules contain, for example, the two components to be mixed together. The components may be those related to filler materials such as, for example, the glass ionomer filler material Ketac™ Molar, or the light-cured glass ionomer filler material Photac™ Fil Quick, or the silver-reinforced glass ionomer filler material Ketac™ Silver Molar, or luting cements such as, for example, the self-adhesive universal composite luting cement RelyX™ Unicem or the adhesive composite luting cement Compolute™ or the glass ionomer luting cement Keta™ Cem.
These known capsules have a cannula, a large mixing chamber which contains the powder and opens at the front into the cannula, a piston which sits at the rear in the mixing chamber, and a foil pouch which contains the liquid and covers a hole in the shell or outer wall of the chamber. To use the capsule, it is first activated by applying pressure in a suitable way to the foil pouch, so that the latter tears near the hole and the liquid is forced into the mixing chamber. The mixing chamber is larger than the combined volume of the two components, so that these can be mixed together by vigorous agitation, for example using the capsule mixer devices RotoMixT™ or CapMixT™ from 3M ESPE. The capsule is then inserted into a suitable applicator that dispenses the mixed material.
The paste/paste capsules contain two pasty components which have to be kept separate from one another until the time of use. Such a paste/paste capsule is known from, for example, WO 2005/016783. The capsule 1, as shown in FIG. 1, comprises a cartridge 2, a first component chamber 4 for containing a first component, and a second component chamber 5 for containing a second component. The two component chambers 4, 5 open into outlets. The capsule 1 also comprises a plunger 70 with a first piston 6 and a second piston 7 being adapted to press the two components out of the component chambers 4, 5 respectively, when the plunger is pushed forward. A common partition wall 14 separates the two component chambers 4, 5 from one another. The nozzle 10, in which a static mixer 11 is accommodated, is pivotably joined with the cartridge 1. The nozzle 10 comprises a bearing member 12 which is arranged in bearing shell 13 of cartridge 1. The nozzle 10, in a first position (not shown), closes off the outlets of the cartridge 1 and, in a second position (shown in FIG. 1), connects the outlets to a passageway of the nozzle 1. The chambers 4, 5 contain the two pasty components which, upon pushing the plunger forward via actuation of an applicator, are expelled from the chambers 4, 5 into the nozzle 10. As they flow through the nozzle 10, the two components become mixed by the static mixer 11 and finally dispensed as a ready-mixed material from the front end of the nozzle 10.